what tip size best for the FM smd ?

[ladybug]

i need to replace my slodering iron tip.

so i could solder them YACs and so on the OPL3 board.

what size of a tip am i looking for ?

[moebius]

What's your desoldering technique?

M

[ladybug]

What's your desoldering technique?

what do mean ?

i smoke some weed, i plugin the iron, then i seat down on a chair in font of a table, holding the iron with my right hand, and then i... solder !

;D ;D ;D

and when i finish i smoke some more

i do not DEsoldering.. only soldering

[moebius]

Noo.. get a good blow, man!

The uCApps site tells you to: go a one pin a time and then suck the solder ;) For this shit, get the smallest tip you can ever get. Period. Good for small tinkering. Period. ( Lame shit for some  engineers, I say!)

For those who just can't spare the time thinkin' - what could be the pin that didn't desolder properly, it's not cummin' out! I'd suggest the proper way..

A big soldering iron tip suggestested (the one heated at the proper electronics soldering temp., mind ya)  -- get the wire as said on the uCApps pages under the side of the pins you are desoldering.

Then apply a plenty of solder at the pins you were to desolder-- let it cool for some time.. maybe smokin' some. NOW it's time for the attack. Keep pulling the wire under pins tight, and move your soldering iron along the pins, keeping all the solder flowing-- Easy wasn't it? You could lift all the pins about the same time? Did it give some extra stress to the IC? Count it by yourself. Maybe less stress, than desoldering a pin a time? Count it by yourself.

Try it out by yourself-- just a technic I copied. If it works, ok - If it doesn't, lets hear from ya.

M

[Davo]

I used a standard tip and used desoldering braid.  There's no need to get a solder-sucker if you don't already have one.  I have one myself, but I found braid to be easier.  Lay the braid over the connections and press the iron to soak up the solder.  When that was done, the pins can be  lifted very easily with the tip of an exacto knife.  Soldering them onto the OPL3 module was another story, but I'm very impressed with the job I did.  I started by pressing the chip to the board with a thumb, then lightly pressing the corner pins.  There is enough solder left on the pins to hold the chip on.  Now to make the permanent connections, carefully approach the pin from the side.  This will melt a bit of solder left on the pin and the tin spread on the board, assuming you bought a professionally made board.  Now briefly touch the pin where it meets the chip body.  Solder will flow down the pin and into the gap between the pin and its pad.  Inspect with a magnifying glass.  If you have access to a dissecting microscope, use that.

[MMorph]

For soldering SMT chips I prefer similar technique as described by Kevin Ross at http://www.kevinro.com/newdocs/learningcenter/surface.htm Click on the video to see how easy it is!

Instead of using paste flux like he does, I use felt-tip pen like no-clean flux pen (liquid content).

Quick summary:

• Presolder the pads if the boards is homebrewed (use only small amount of solder)
  
• Apply some flux over the pads on PCB (don't soak it, but having too little of flux is bigger problem)
  
• Align the part on PCB and heat the opposite corner pins to get your component hold on its place
  
• Slowly drag the soldering iron across the pads, close to the pins of the component. If there was right amount of solder on pads, there wont be any bridges to be removed and the result is top notch!
  

Actually this result can be achieved even if you don't have the smallest tip attached on your soldering iron. So maybe you don't even need to buy a new tip, unless your current tip is really huge :) On the other hand, using this method you need to buy some flux unless you happen to have some available by the time.

Regards, Petri